In the municipal waste incineration process, due to high steam pressure, mercury and its derivates (for example, mercuric chloride) are easily evaporated and exhausted with emissions in the high-temperature environment in the incinerator, thereby causing environmental pollution.
Activated carbon is a medium capable of adsorbing organics and heavy metal pollutants. However, since the temperature of the incineration emission is as high as 150° C., the adsorption performance of activated carbon is significantly reduced, so it has been proposed to add other chemicals to modify activated carbon in the prior art, so as to improve the high-temperature adsorption performance of activated carbon.
For example, in a method for preparing sulfur-containing powdered activated carbon disclosed in Taiwan Patent Publication No. 574139, a carbonaceous raw material is subjected to pyrolysis, and a sulfur-containing solution is introduced during the pyrolysis, so as to obtain sulfur-containing powdered activated carbon.
However, the sulfur-containing powdered activated carbon prepared in the method can effectively adsorb divalent mercury, and has limited adsorption effect on elemental mercury having a great threat to human health even in a trace amount.
Therefore, it is necessary to provide a method for preparing composite sulfur-modified powdered activated carbon to solve the foregoing problems.